Emergency breathing apparatus

ABSTRACT

In emergency breathing apparatus a case has a back section and a removable front cover section that are normally held together. Inside the case an air regenerating canister is secured to the back section and has a port in one end, to which a flexible breathing hose is connected. The opposite end of the canister is provided with an opening in each side, each of which is connected with an opening in one end of a breathing bag extending along that side of the canister. The hose and bags normally are folded within the case. The other ends of the bags are connected by means formed to extend around the back of the neck of a user of the apparatus to suspend the bags over his chest when they are removed from the case, with the canister between the bags.

United States Patent Cotabish et al. [451 Apr. 11, 1972 54] EMERGENCYBREATHING 2,758,015 8/1956 Bovard m1 .....23/281 APPARATUS 2,004,2436/1935 Hloch ..23/221 [72] Inventors: Harry N. Cotabish, Allison Park;Layton A. Wise, Washington; Elmer E. Buban,

Monroeville, all of Pa.

[73] Assignee: Mine Safety Appliances Company, Pittsburgh, Pa.

[22] Filed: Feb. 19, 1970 [21] Appl. No: 12,201

[52] U.S. Cl. .23/281, 23/221, 23/252 R, 128/202, 128/191 R, 128/1426,55/518 [51] lnt. C1. .B0lj 7/00 [58] Field of Search ..128/202, 142,142.3, 191, 142.6, 128/1427; 23/281, 252, 221; 55/518, 512, 515

[56] References Cited UNITED STATES PATENTS 2,403,981 7/1966 Jackson eta1 ..l28/191 R Primary Examiner-James H. Tayman, Jr. Att0rneyBrown,Murray, Flick & Peckham [57] ABSTRACT In emergency breathing apparatus acase has a back section and a removable front cover section that arenormally held together. Inside the case an air regenerating canister issecured to the back section and has a port in one end, to which aflexible breathing hose is connected. The opposite end of the canisteris provided with an opening in each side, each of which is connectedwith an opening in one end of a breathing bag extending along that sideof the canister. The hose and bags normally are folded within the case.The other ends of the bags are connected by means formed to extendaround the back of the neck of a user of the apparatus to suspend thebags over his chest when they are removed from the case, with thecanister between the bags.

5 Claims, 4 Drawing Figures .O I g 4 O 01 r 5 O 32 O O o 3.9 O

4/ 4/ I as PATENTEDAPR 1 1 I972 SHEET 1 OF 2 IN VENTORS.

v, H E 5 mew ww m u m WW MAE. A 0% a HLE EMERGENCY BREATHING APPARATUSIt is among the objects of this invention to provide emergency breathingapparatus which is neat and compact, which is hermetically sealed, whichcan be opened quickly and easily and set in operation without delay, andin which breathing bags support an air regenerating canister.

The preferred embodiment of the invention is illustrated in theaccompanying drawings, in which FIG. 1 is a front view of the apparatusin operative conditron;

FIG. 2 is an enlarged fragmentary front view of the apparatus, showingthe canister partly in section;

FIG. 3 is a longitudinal section taken on the line lIIlll of FIG. 2; and

FIG. 4 is a reduced side view of the closed case.

Referring to the drawings, a rectangular case is formed from a shallowback or base 1 and a deep cover 2. These are provided with side wallssurrounded by outwardly extending flanges 3 (FIG. 3) at their freeedges. Inside the case and spaced from its side walls there is arectangular canister 4 containing a carbon dioxide absorbing and oxygenproducing chemical, such as potassium superoxide. The canister isprovided with end lugs 5, by which it is secured to the base, from whichthe canister extends well into the cover as indicated by dotted lines inFIG. 3.

As shown in FIG. 1, one end of the canister, which is the upper end whenit is in use, is provided with a combined inlet and outlet port 7, towhich one end of a flexible breathing hose 8 is connected. The other endof the hose is provided with a mouthpiece 9 and a nose clip 10. Theopposite end of the canister is provided in its side walls with openingsthat are connected by short tubular fittings 12 to the lower parts of apair of breathing bags 13. The upper ends of these bags are integrallyconnected by a band 14 that will extend around the back of the neck ofthe user of this apparatus to suspend the bags over the chest. The hoseand the breathing bags normally are folded into the case in the spacesbetween the canister and the case.

In order to seal the case so that the chemical in the canister will notdeteriorate, a flexible sealing gasket 16 is disposed between the caseflanges in engagement with them, as shown in FIGS. 3 and 4. The case isheld closed, with the gasket clamped between the flanges, by quickrelease means, such as a clamping wire 17 (FIG. 4) that surrounds thegasket. The wire is bent in a more or less zig-zag fashion to form tworows of longitudinally spaced loops that extend inwardly over the caseflanges and press them toward each other. The two rows of loops have tobe sprung apart somewhat in order to apply them to the case, so theypress the flanges toward each other and tightly against the gasket. Itwill be seen that in order to open the case, the clamping wire must beremoved. This is done by pulling outwardly on one end of it to strip itaway from the case flanges. For this purpose a pull tab 18 may befastened to one end of the wire. It is obvious that the case can beopened in only a matter of seconds and the breathing bags hung aroundthe neck, whereupon they will support the canister in upright positionbetween them, and the canister will support the back portion of the caseagainst the chest. Of course, the cover of the case is laid aside ordiscarded.

Another feature of this invention is that in spite of the use of a smallcase the canister inside of it is very efficient for its small sizebecause it is so constructed and arranged that it provides for a largecross-sectional flow area through the chemical for low breathingresistance. It also is provided with an oxygen candle to immediatelygenerate oxygen before the potassium superoxide starts to function. Asshown in F IGS. 2 and 3, the candle 25 rests on the bottom of theupright canister housing and is ignited in the usual way by a primerthat is struck by a pivoted firing pin 26 (FIG. 3) moved by a spring 27when a safety pin 28 is pulled. Immediately above the candle there is apartition or shelf 29 that extends from side to side of the canister andthat is attached to its front wall as well as its sides to divide thecanister into a tall upper chamber and a short lower chamber. Thecanister is provided at the back with a passage 30 past the partition toconnect the two chambers. This may be done by openings in the partition,or by spacing it from the back of the canister housing, in which casethe rear edge of the shelf is turned up to form a flange 31.

Fittings 12 for the breathing bags are at the opposite sides of thelower chamber containing the candle. Port 7 is is in the front of thetop wall of the canister.

Resting on the front of shelf 29 is the lower end of an inclinedperforated metal plate 32, the upper end of which is directly behind theport 7. This plate is spaced from the front of the canister housing byintegral downwardly tapered side flanges 33 that engage the front wall.Immediately behind the plate there is a thin mat 34 of filteringmaterial and then a screen 35. Behind the screen there is the bed ofpotassium superoxide 36 and then another screen 37, another filter mat38, and another perforated metal plate 39 resting on the back of theshelf. This plate is held in inclined position, spaced from the back ofthe canister, by means of a spring 40 compressed between it and the backwall. It also is desirable to provide molecular sieves 41 between thechemical bed and the screens. The sieves absorb moisture to reduce orprevent over production of oxygen and thereby extend the life of thechemical bed. Also, if the chemical absorbs too much moisture it maysoften and run and tend to clog the filters, which would increase thebreathing resistance. The molecular sieves help to prevent this fromhappening.

Air exhaled into the canister through the hose can flow down to shelf 29and thus enter the chemical bed through the large area of plate 32. Theair, with carbon dioxide removed from it and enriched with oxygen,leaves the chemical through the entire area of plate 39 and then flowsdownwardly behind the shelf and into the breathing bags. With such alarge area of the chemical exposed to the air, breathing resistance isheld to a minimum during both exhalation and the return inhalation, eventhough the canister must be kept small to fit in the case.

Since considerable heat is generated in the canister by the chemicalreaction, it is desirable to provide means for cooling the air beinginhaled. This can be done by trapping moisture from the exhaled breathand then returning that moisture to the inhaled air to cool it. Thereturned moisture also humidifies the dry air. Suitable means foraccomplishing this purpose is a roll of metal screen 43 placed in asection of the breathing hose, as shown in FIG. 1, where it is held inplace by frictional engagement with the hose. Exhaled air passingthrough the screen roll deposits moisture on it, but during inhalationthis moisture is picked up by the incoming dry air which is therebyhumidified and cooled due to evaporation of the trapped moisture.

This small, self-contained breathing apparatus remains sealed andoperative until the case is opened. It is quickly hung in place withoutthe use of straps or other fasteners. The canister occupies the spacebetween the breathing bags and projects only a short distance forwardfrom the chest. Yet, due to its construction and the way in which it issuspended, it has considerable capacity and effectiveness.

We claim:

1. An air regenerating canister comprising a rectangular housing havingfront and back walls connected by side walls and end walls, the housingbeing provided with an inlet-outlet port in one end and with an openingin each side wall adjacent the opposite end of the housing, a transversepartition in the housing extending from side to side thereof adjacentsaid openings but between them and said port, the partition extendingrearwardly from said front wall to form a short chamber between saidopenings that is defined by said partition and front and back and sidewalls and the nearest end wall, a long chamber being formed by the restof the housing between the partition and said port, the housing beingprovided at the back with a passage past said partition for connectingsaid chambers, an air purifying and oxygen producing chemical bed insaid long chamber between said passage and port, at least the majorportion of said bed being spaced from said front and back walls, thespace in front of the bed communicating with said port and the spacebehind the bed communicating with said passage, an oxygen candle in saidshort chamber, and manually operable means outside of said housing forigniting the candle.

2. An air regenerating canister according to claim 1, said inlet-outletport being adjacent the front wall of the housing, the canisterincluding a perforated plate in said long chamber engaging saidpartition and inclined backwardly therefrom to a point behind said port,the plate having tapered side flanges spacing it from the front wall, afilter mat engaging the back of the plate, a first screen engaging theback of the mat, a second screen spaced behind the first screen withsaid chemical bed between them, a filter mat behind the second screen,an inclined perforated plate engaging said partition behind the secondmat, and a spring between the back plate and the back wall of thehousing and pressing the back plate forward.

3. An air regenerating canister according to claim 2, the canister alsoincluding molecular sieves between said chemical bed and screens.

4. An air regenerating canister according to claim 1, said inlet-outletport being adjacent the front wall of the housing and opening into theadjacent end of the space between the chemical bed and said front wall,the canister including perforated means holding said bed spaced from thefont and back walls.

5. An air regenerating canister according to claim 1, said inlet-outletport being adjacent the front wall of the housing and opening into theadjacent end of the space between the chemical bed and said front wall,the canister including perforated plates substantially coextensive withthe front and back of said bed, one of said plates having side flangesspacing it from the adjacent canister wall facing that plate, andresilient means compressed between the other plate and the canister wallfacing it and urging them apart.

2. An air regenerating canister according to claim 1, said inlet-outletport being adjacent the front wall of the housing, the canisterincluding a perforated plate in said long chamber engaging saidpartition and inclined backwardly therefrom to a point behind said port,the plate having tapered side flanges spacing it from the front wall, afilter mat engaging the back of the plate, a first screen engaging theback of the mat, a second screen spaced behind the first screen withsaid chemical bed between them, a filter mat behind the second screen,an inclined perforated plate engaging said partition behind the secondmat, and a spring between the back plate and the back wall of thehousing and pressing the back plate forward.
 3. An air regeneratingcanister according to claim 2, the canister also including molecularsieves between said chemical bed and screens.
 4. An air regeneratingcanister according to claim 1, said inlet-outlet port being adjacent thefront wall of the housing and opening into the adjacent end of the spacebetween the chemical bed and said front wall, the canister includingperforated means holding said bed spaced from the font and back walls.5. An air regenerating canister according to claim 1, said inlet-outletport being adjacent the front wall of the housing and opening into theadjacent end of the space between the chemical bed and said front wall,the canister including perforated plates substantially coextensive withthe front and back of said bed, one of said plates having side flangesspacing it from the adjacent canister wall facing that plate, andresilient means compressed between the other plate and the canister wallfacing it and urging them apart.